Certain aryloxyphenoxy oxoimidazolidines and method of use

ABSTRACT

As new compounds, aryloxyphenoxy oxoimidazolines having the formula &lt;IMAGE&gt;   wherein A is CH or nitrogen; X is hydrogen or chlorine; and R and R1 are alkyl groups having from 1 to 4 carbon atoms.

BACKGROUND OF THE INVENTION

The present invention relates to certain aryloxyphenoxy oxoimidazolinecompounds which are particularly useful as post-emergent herbicidesagainst annual and perennial grasses.

Herbicides are widely used by farmers, commercial agriculturalcompanies, and other industries in order to increase crop yields forsuch staple crops as corn, soybeans, rice, and the like, and toeliminate weed growth along highways, railroad rights-of-way, and otherareas. Herbicides are effective in killing or controlling unwanted weedswhich compete for soil nutrients with the crop plants, and by reason ofthe fact that they kill weeds, are responsible for improving theaesthetic appearance of highway and railroad rights-of-way.

There are a number of different types of herbicides presently soldcommercially, and these fall into two general categories. The categoriesare pre-emergence and post-emergence herbicides. The pre-emergenceherbicides are normally incorporated into or applied to the soil priorto the emergence of the weed plants from the soil, and thepost-emergence herbicides are normally applied to plant surfaces afteremergence of the weeds or other unwanted plants from the soil.

THE PRIOR ART

The prior art is replete with examples of aryloxyphenoxy propionicacid-type compounds which have been disclosed to be herbicidallyeffective against grasses in particular, as compared to broad leaf weedpests. Examples of such prior art references include U.S. Pat. Nos.4,200,587 and 4,325,729, both of which disclose aryloxyphenoxy propionicacid derivatives as being effective herbicides against grasses.

Efforts are constantly being made, however, to find compounds which areequal to or greater in effectiveness than presently existing compounds,or which are more economical to produce.

DESCRIPTION OF THE INVENTION

It has now been discovered that certain new and novel aryloxyphenoxyoxoimidazolines have good herbicidal and plant growth regulatingactivity, particularly when applied as post-emergent herbicides and usedagainst annual and perennial grasses.

As used herein, the term "herbicide" means a compound or compositionwhich controls or modifies the growth of plants. By the term"herbicidally effective amount" is meant any amount of such compound orcomposition which causes a modifying effect upon the growth of plants.By "plants" is meant germinant seeds, emerging seedlings and establishedvegetation, including roots and above-ground portions. Such controllingor modifying effects include all deviations from natural development,such as killing, retardation, defoliation, desiccation, regulation,stunting, tillering, leaf burn, dwarfing and the like.

The new and novel compounds of this invention are2-[1-(4-aryloxyphenoxy)-ethyl]-5,5-dialkyl-4-oxoimidazolines.

Of these oxoimidazolines certain ones are preferred. The preferredcompounds have the formula ##STR2## wherein A is CH or nitrogen;

X is hydrogen or chlorine; and

R and R₁ are alkyl groups having from 1 to 4 carbon atoms.

The most preferred compound for use in the practice of the invention2-[1-(5-trifluoromethyl-2-pyridoxy)phenoxy]-ethyl-5,5-methyl-4-oxoimidazoline,

Other preferred compounds falling within the generic formula set forthabove include:2-[1-(5-trifluoromethylphenoxy)phenoxy]-ethyl-5,5-dimethyl-4-oxoimidazoline;and2-[2-(5-trifluoromethyl-3-chloro-2-pyridyloxy)phenoxy]ethyl-5,5-dimethyl-4-oxoimidazoline.

The compounds of this invention can be made by reacting anN-(cyanomethyl)propionamide with hydrochloric acid, to form anintermediate N-carbamoylmethyl aryloxyphenoxyamide, and reacting thisamide in turn with thionyl chloride to form the end product.

This is illustrated by the reaction sequence as follows: ##STR3##

Examples 1 and 2 below illustrate the method of making the compounds ofthe invention.

EXAMPLE 1 Preparation ofN-(2-cyano-isopropyl)2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]-propionamide,A

Four grams (0.0116 mole) of2-[4-(5-trifluoromethyl-2-pyridyloxy)-propionyl chloride were chargedinto a round-bottom flask immersed in an ice bath containing 30 ml ofmethylene chloride to which was added 0.96 ml of pyridine over a 30minute period and 1 gram (0.119 mole) of 2-cyanoisopropylamine dissolvedin 10 ml of methylene chloride was added over a 45 minute period. Thecontents were stirred over the weekend and thereafter was partitionedbetween methylene chloride and water. The methylene chloride solutionwas then washed with one molar hydrochloric acid, and rotary vacuumed toyield 4.0 g of product which was identified by suitable techniques asbeing the subject compound.

EXAMPLE 2 Preparation of2-[1-(5-trifluoromethylpyridoxyphenoxy)-ethyl]-5,5-methyl-4-oxoimidazoline

One gram (1 g, 0.00254 mole) of aryloxyphenoxy amide A was charged intoa round-bottom flask immersed in an ice bath and containing 25milliliters (ml) of 4N hydrochloric acid. The solution was stirred forone hour while in the ice bath, then at room temperature for 18 hours.Thereafter, the reaction mixture was filtered, the filtrate dissolved inethyl alcohol and dried over magnesium sulfate, It was then rotaryvacuumed to yield 0.63 g of intermediate pyridoxyphenoxy amide B.

Thereafter 0.3 g (0.0073 mole) of the amide B was charged into a roundbottom flask containing 5 ml of thionyl chloride. After reflux for 2.5hours the thionyl chloride was rotary vacuumed off, and the residuedissolved in a methylene chloride/water solution, washed with brine, andthen dried over magnesium sulfate. The solution was then again rotaryvacuumed to yield 0.27 g of product which was identified by suitableanalytical techniques as being the subject compound.

Similar techniques can be used to prepare the other compounds fallingwithin the purview of this invention.

The preferred compound, as set forth above, has been found to haveespecially good herbicidal activity against perennial and annual grasseswhen applied as a post-emergent herbicide. It is also effective as apre-emergent herbicide and plant growth regulator, but not to the sameextent as when applied post-emergent.

The herbicidal activity of representative ones of the compounds of theinvention as exhibited by means of tests in accordance with thefollowing procedure.

EXAMPLE 3 Herbicidal Activity Tests

This example offers herbicidal activity test data to show theeffectiveness of the oxoimidazolidine compounds of the invention. Theeffect is observed by comparing the extent of weed control in test flatstreated with the compounds against that occurring in similar controlflats. The soil used in these tests was a sandy loam soil from theLivermore, Calif. area.

Also added to the soil was 17-17-17 fertilizer (N-P₂ O₅ -K₂ O on aweight basis), amounting to 50 ppm by weight with respect to the soiland 100 ppm Captan, a soil fungicide.

The treated soil was then placed in flats which were 3 inches deep, 6inches wide, and 10 inches long. The soil was tamped and leveled with arow marker to impress six rows across the width of the flat. The testweeds were as follows:

    ______________________________________                                        COMMON NAME     SCIENTIFIC NAME                                                                              ABR                                            ______________________________________                                        Broadleaf Weeds:                                                              annual morningglory                                                                           Ipomoea purpurea                                                                             AMG                                            velvetleaf      Abutilon theophrasti                                                                         VL                                             mustard         Brassica sp.   MD                                             curly dock      Rumex crispus  CD                                             Grasses:                                                                      yellow nutsedge Cyperus exculentus                                                                           YNS                                            foxtail         Setaria sp.    FT                                             watergrass      Echinochloa crusgalli                                                                        WG                                             wild oat        Avena fatua    WO                                             ______________________________________                                    

Sufficient seeds were planted to produce several seedlings per inch ineach row. The flats were then placed in a greenhouse maintained at 70°to 85° F. (21° to 30° C.) and watered daily by sprinkler.

In the case of pre-emergent testing the herbicide was incorporated intothe soil prior to planting of the seeds, at a rate equivalent to theindicated amounts in the Table.

In post-emergent testing chemical application is made by spraying 12days after planting. The spray solution is prepared by dissolving 60 mgof herbicide compound in 20 ml of acetone containing 1% Tween® 20(polyoxysorbitan monolaurate), then adding 20 ml of water to theresulting solution. The soution is sprayed at 80 gallon/acre, resultingin a 4 lb/acre rate of chemical application. Other rates were achievedby varying the solution concentration and/or the rate of spray.

In both instances, either pre- or post-emergence testing, approximately12-14 days after treatment, the degree of weed control was estimated andrecorded as percentage control compared to the growth of the samespecies in an untreated check flat of the same age. The rating scaleranges from 0 to 100%, where 0 equals no effect with plant growth equalto the untreated control, and 100 equals complete kill.

The results are listed in the Table below.

                                      TABLE I                                     __________________________________________________________________________    HERBICIDE TEST RESULTS                                                                   Application Percent Control                                        TEST COMPOUND                                                                            Rate (lb/A)                                                                          Method                                                                             FT WG WO AMG VL MD CD YNS                              __________________________________________________________________________     1*        4      PRE  100                                                                               95                                                                              60 0   0  0  0  0                                1          4      POST 100                                                                              100                                                                              90 0   0  0  0  0                                __________________________________________________________________________     *2-[1(5-trifluoromethylpyridyoxy)phenoxyethyl5,5-dimethyl-4-oxoimidazolin                                                                              

METHODS OF APPLICATION

The herbicidal compositions of the present invention are useful incontrolling the growth of undesirable vegetation by pre-emergence orpost-emergence application to the locus where control is desired,including pre-plant and post-plant soil incorporation as well as surfaceapplication. Foliar application is preferred. The compositions aregenerally embodied in formulations suitable for convenient application.Typical formulations contain additional ingredients or diluent carrierswhich are either inert or active. Examples of such ingredients orcarriers are water, organic solvents, dust carriers, granular carriers,surface active agents, oil and water, wateroil emulsions, wettingagents, dispersing agents, and emulsifying agents. The herbicidalformulations generally take the form of dusts, emulsifiableconcentrates, granules and pellets, or microcapsules.

A. DUSTS

Dusts are dense powder compositions which are intended for applicationin dry form. Dusts are characterized by their free-flowing and rapidsettling properties so that they are not readily windborne to areaswhere their presence is not desired. They contain primarily an activematerial and a dense, free-flowing, solid carrier.

Their performance is sometimes aided by the inclusion of a wettingagent, and convenience in manufacture frequently demands the inclusionof an inert, absorptive grinding aid. For the dust compositions of thisinvention, the inert carrier may be either of vegetable or mineralorigin, the wetting agent is preferably anionic or nonionic, andsuitable absorptive grinding aids are of mineral origin.

Suitable classes of inert solid carriers for use in the dustcompositions are those organic or inorganic powders which possess highbulk density and are very free-flowing. They are also characterized bylow surface area and poor liquid absorptivity. Suitable grinding aidsare natural clays, diatomaceous earths, and synthetic mineral fillersderived from silica or silicate. Among ionic and nonionic wettingagents, the most suitable are the members of the group known to the artas wetting agents and emulsifiers. Although solid agents are preferredbecause of ease of incorporation, some liquid nonionic agents are alsosuitable in the dust formulations.

Preferred dust carriers are micaceous talcs, pyrophyllite, dense kaolinclays, tobacco dust and ground calcium phosphate rock.

Preferred grinding aids are attapulgite clay, diatomaceous silica,synthetic fine silica and synthetic calcium and magnesium silicates.

Most preferred wetting agents are alkylbenzene and alkyl-naphthalenesulfonates, sulfated fatty alcohols, amines or acid amides, long chainacid esters of sodium isothionate, esters of sodium sulfosuccinate,sulfated or sulfonated fatty acid esters, petroleum sulfonates,sulfonated vegetable oils, and ditertiary acetylenic glycols. Preferreddispersants are methyl cellulose, polyvinyl alcohol, lignin sulfonates,polymeric alkylnaphthalene sulfonates, sodium naphthalenesulfonate,polymethylene bisnaphthalenesulfonate, and sodium-N-methyl-N-(long chainacid) taurates.

The inert solid carriers in the dusts of this invention are usuallypresent in concentrations of from about 30 to 90 weight percent of thetotal composition. The grinding aid will usually constitute 5 to 50weight percent of the compositions, and the wetting agent willconstitute from about 0 to 1.0 weight percent of the composition. Dustcompositions can also contain other surfactants such as dispersingagents in concentrations of up to about 0.5 weight percent, and minoramounts of anticaking and antistatic agents. The particle size of thecarrier is usually in the range of 30 to 50 microns.

B. EMULSIFIABLE CONCENTRATES

Emulsifiable concentrates are usually solutions of the active materialsin nonwater-miscible solvents together with an emulsifying agent. Priorto use, the concentrate is diluted with water to form a suspendedemulsion of solvent droplets.

Typical solvents for use in emulsifiable concentrates include weed oils,chlorinated hydrocarbons, and nonwater-miscible ethers, esters, andketones.

Typical emulsifying agents are anionic or nonionic surfactants, ormixtures of the two. Examples include long-chain alkyl or mercaptanpolyethoxy alcohols, alkylaryl polyethoxy alcohols, sorbitan fatty acidesters, polyoxyethylene ethers with sorbitan fatty acid esters,polyoxyethylene glycol esters with fatty or rosin acids, fatty alkylolamide condensates, calcium and amine salts of fatty alcohol sulfates,oil soluble petroleum sulfonates, or preferably mixtures of theseemulsifying agents. Such emulsifying agents will comprise from about 1to 10 weight percent of the total composition.

Thus, emulsifiable concentrates of the present invention will consist offrom about 15 to about 50 weight percent active material, about 40 to 82weight percent solvent, and about 1 to 10 weight percent emulsifier.Other additives such as spreading agents and stickers can also beincluded.

C. GRANULES AND PELLETS

Granules and pellets are physically stable, particulatecomposicompositions containing the active ingredients adhering to ordistributed through a basic matrix of a coherent, inert carrier withmicroscopic dimensions. A typical particle is about 1 to 2 millimetersin diameter. Surfactants are often present to aid in leaching of theactive ingredient from the granule or pellet.

The carrier is preferably of mineral origin, and generally falls withinone of two types. The first are porous, absorptive, preformed granules,such as preformed and screened granular attapulgite or heat expanded,granular, screened vermiculite. On either of these, a solution of theactive agent can be sprayed and will be absorbed at concentrations up to25 weight percent of the total weight. The second, which are alsosuitable for pellets, are initially powdered kaolin clays, hydratedattapulgite, or bentonite clays in the form of sodium, calcium, ormagnesium bentonites. Water-soluble salts, such as sodium salts, mayalso be present to aid in the disintegration of granules or pellets inthe presence of moisture. These ingredients are blended with the activecomponents to give mixtures that are granulated or pelleted, followed bydrying, to yield formulations with the active compound distributeduniformly throughout the mass. Such granules and pellets can also bemade with 25 to 30 weight percent active component, but more frequentlya concentration of about 10 weight percent is desired for optimumdistribution. The granular compositions of this invention are mostuseful in a size range of 15-30 mesh.

The surfactant is generally a common wetting agent of anionic ornonionic character. The most suitable wetting agents depend upon thetype of granule used. When preformed granules are sprayed with activematerial in liquid form the most suitable wetting agents are nonionic,liquid wetters miscible with the solvent. These are compounds mostgenerally known in the art as emulsifiers, and comprise alkylarylpolyether alcohols, alkyl polyether alcohols, polyoxyethylene sorbitanfatty acid esters, polyethylene glycol esters with fatty or rosin acids,fatty alkyol amide condensates, oil solution petroleum or vegetable oilsulfonates, or mixtures of these. Such agents will usually comprise upto about 5 weight percent of the total composition.

When the active ingredient is first mixed with a powdered carrier andsubsequently granulated, or pelleted, liquid nonionic wetters can stillbe used, but it is usually preferable to incorporate at the mixing stageone of the solid, powdered anionic wetting agents such as thosepreviously listed for the wettable powders. Such agents will comprisefrom about 0 to 2 weight percent of the total composition.

Thus, the preferred granular or pelleted formulations of this inventioncomprise about 5 to 30 percent by weight active material, about 0 to 5weight percent wetting agent, and about 65 to 95 weight percent inertmaterial carrier, as these terms are used herein.

D. MICROCAPSULES

Microcapsules consist of fully enclosed droplets or granules containingthe active materials, in which the enclosing material is an inert porousmembrane, arranged to allow escape of the enclosed materials to thesurrounding medium at controlled rates over a specified period.Encapsulated droplets are typically about 1 to 50 microns in diameter.

The enclosed liquid typically constitutes about 50 to 95% of the weightof the entire capsule, and may contain a small amount of solvent inaddition to the active materials.

Encapsulated granules are characterized by porous membranes sealing theopenings of the granule carrier pores, trapping the liquid containingthe active components inside for controlled release. A typical granulesize ranges from 1 millimeter to 1 centimeter in diameter. Inagricultural useage, the granule size is generally about 1 to 2 ml indiameter. Granules formed by extrusion, agglomeration, or prilling areuseful in the present invention as well as materials in their naturallyoccurring form. Examples of such carriers are vermiculite, sintered claygranules, kaolin, attapulgite clay, sawdust, and granular carbon.

Useful encapsulating materials include natural and synthetic rubbers,cellulosic materials, styrene-butadiene copolymers, polyacrylonitriles,polyacrylates, polyesters, polyamides, polyurethanes, and starchxanthates.

E. IN GENERAL

Each of the above formulations can be prepared as a package containingthe herbicide together with the other ingredients of the formulation(diluents, emulsifiers, surfactants, etc.). The formulations can also beprepared by a tank mix method, in which the ingredients are obtainedseparately and combined at the grower site.

In general, any conventional method of application can be used. Thelocus of application can be soil, seeds, seedlings, or the actualplants, as well as flooded fields. Post-emergent application ispreferred. Dusts and liquid compositions can be applied by the use ofpowder dusters, boom and hand sprayers, and spray dusters. Thecompositions can also be applied from airplanes as dusts and spraysbecause they are effective in very low dosages. In order to modify orcontrol the growth of germinating seeds or emerging seedlings, as atypical example, the dust and liquid compositions are applied to thesoil according to conventional methods and are distributed in the soilto a depth of at least one-half inch below the soil surface. It is notnecessary that the phytotoxic compositions be admixed with the soilparticles. Instead, these compositions can be applied merely by sprayingor sprinkling the surface of the soil. The phytotoxic compositions ofthis invention can also be applied by addition to irrigation watersupplied to the field to be treated. This method of application permitsthe penetration of the compositions into the soil as the water isabsorbed therein. Dust compositions, granular compositions or liquidformulations applied to the surface of the soil can be distributed belowthe surface of the soil by conventional means such as discing, draggingor mixing operations.

The herbicide composition can also be applied to the soil throughirrigation systems. According to this technique, the compositions areadded directly to irrigation water immediately prior to irrigation ofthe field. This technique is applicable in all geographical areasregardless of rainfall, since it permits supplementation of the naturalrainfall at critical stages of plant growth. In a typical application,the concentration of the herbicide composition in the irrigation waterwill range from about 10 to 150 parts per million by weight. Theirrigation water can be applied by the use of sprinkler systems, surfacefurrows, or flooding. Such application is most effectively done beforethe weeds germinate, either early in the spring prior to germination orwithin two days after cultivation of the field.

The amount of the present composition which constitutes a herbicidallyeffective amount depends upon the nature of the seeds or plants to becontrolled. The rate of application of active ingredient varies fromabout 0.01 to about 50 pounds per acre, preferably about 0.1 to about 25pounds per acre with the actual amount depending on the overall cost andthe desired results. It will be readily apparent to one skilled in theart that compositions exhibiting lower herbicidal activity will requirea higher dosage than more active compounds for the same degree ofcontrol.

What is claimed is:
 1. An aryloxyphenoxyoxoimidazoline having theformula ##STR4## wherein A is CH or nitrogen;X is hydrogen or chlorine;and R and R₁ are alkyl groups having from 1 to 4 carbon atoms.
 2. Thecompound of claim 1 in which A is CH.
 3. The compound of claim 1 inwhich X is chlorine.
 4. The compound of claim 1 in which R and R₁ aremethyl.
 5. The compound of claim 1 in which A is nitrogen.
 6. Aherbicidal composition which comprises a herbicidally effective amountof an aryloxyphenoxyoxoimidazoline having the formula ##STR5## wherein Ais CH or nitrogen;X is hydrogen or chlorine; and R and R₁ are alkylgroups having from 1 to 4 carbon atoms and an inert diluent carrier. 7.The composition of claim 6 in which A is CH.
 8. The composition of claim6 in which X is chlorine.
 9. The composition of claim 6 in which R andR₁ are methyl.
 10. The composition of claim 6 in which A is nitrogen.11. A method for controlling undesirable grasses which comprisesapplying to the locus where control is desired a herbicidally effectiveamount of a compound having the formula ##STR6## wherein A is CH ornitrogen;X is hydrogen or chlorine; and R and R₁ are alkyl groups havingfrom 1 to 4 carbon atoms.
 12. The method of claim 11 in which A is CH.13. The method of claim 11 in which X is chlorine.
 14. The method ofclaim 11 in which R and R₁ are methyl.
 15. The method of claim 11 inwhich A is nitrogen.